Over-voltage conditions can damage electronic devices, including transistors, regulators, and loads. High-voltage transient devices such as for automotive often use devices capable of operating with high voltages, so that the devices are not damaged during high voltage transients, such as load dump conditions.
A load dump condition may occur in an automobile due to an abrupt change in alternator load. For example, headlights being turned off, or the battery being disconnected from the battery post by a shock or mechanical vibration, may cause a load dump condition. The load dump condition may cause a large increase in voltage. The battery line, normally having a voltage of around 12 Volts, may have a voltage spike going to 50V or more during the load dump condition. To accommodate such high voltage spikes, devices capable of operating at such voltages may be used. However, such high-voltage devices are typically significantly more expensive and/or limited in availability.